This was a monthly scientific publication which covered hobbies
and inventions of the day. This issue contains a number of interesting
stories such as: Edison's Famous Insomnia Squad; a Guest Editorial by J.
Edgar Hoover on the value of fingerprint identification; Major
Alexander P. de Seversky, Flying Inventor; Sound Engineers of NBC Radio
studios; preparing for the 1939 New York World's Fair; model aircraft
building; plus much more. Well illustrated throughout and containing
many period advertisements.